Here are some fish facts from Jen Reynolds, a tropical freshwater aquarist at the Vancouver Aquarium Marine Science Centre. They'll get you started and prevent little Nemo from getting stressed.

• Use a tank that allows as much surface area as possible. Reynolds recommends a 30-gallon tank with a good filtration system.

• Pay close attention to water temperature. For tropical freshwater fish, 26.5 C to 28.5 C is appropriate. For cold-water fish, the temperature is a little different for each. For example, 14 C to 22 C for a goldfish.

• Create a habitat that suits your fishes' natural behaviours.

• Choose compatible fish (it's a fish-eat-fish world out there).

• Change 30 per cent of the tank water every two weeks.

Tropical freshwater
Platy, $3 to $5
Baby making: Live-bearer (has live babies
Swims: Near surface
Social habits: Prefers to be with others of its own kind
Food: Tropical-fish community flakes and bloodworms
Special feature: Easy to tell males from females

Guppy, $3 to $6
Baby making:Live-bearer
Swims: Near surface
Social habits: Prefers to be with other
Food: Tropical-fish community flakes and bloodworms
Special feature: Easy to tell males from females

Zebra danio, $2 to $5
Baby making: Egg layer
Swims: At mid-level
Social habits: Schooling fish
Food: Tropical-fish community flakes and bloodworms
Special feature: Fast moving

Keyhole cichlid, $5 to $10
Baby making: Egg layer
Swims: At mid-level
Social habits: Prefers to have at least one buddy
Food: Tropical-fish community flakes and bloodworms
Special feature: Enjoys interesting objects to hide in/behind

Harlequin rasbora, $3 to $6
Baby making: Egg layer
Swims:At mid-level
Social habits: Schooling fish
Food: Tropical-fish community flakes and bloodworms
Special feature: Interesting colour and markings

Corydoras catfish, $3 to $5 (rare varieties are more expensive
Baby making: Egg layer
Swims: At bottom
Social habits: Prefers to have a couple of buddies
Food: Fish/catfish pellets (that will fall to the bottom) and bloodworms
Special feature: Searches around in the gravel

Flying fox, $3 to $10
Baby making: Egg layer
Swims: At all levels
Social habits: Can be territorial with other of its kind
Food: Tropical-fish community flakes and bloodworms
Special feature: Will eat algae from the glass and plants

Cold/unheated water
Goldfish, $1 to $50, depending on size
Baby making: Egg layer
Swims: At mid-level
Social habits: Prefers at least one goldfish buddy
Food: Goldfish flakes
Special feature: Needs a well-filtered tank, not a bowl

White cloud mountain minnow, $2 to $3
Baby making: Egg layer
Swims: Primarily at mid-level
Social habits: Schooling fish
Food: Fish flakes
Special feature: Fast moving